Uses of white corn hybrids

ABSTRACT

The present invention provides hybrid white corn that produces grain with novel compositional characteristics, such as, higher endosperm protein concentration and low levels of carotenoids. The compositional changes facilitate the use of an improved process for wet milling of white corn and improve the characteristics and performance of the products derived therefrom. A high protein, nearly carotene-free corn gluten meal and substantially pure starch are extracted from this white corn having a unique genotype, a unique kernel phenotype and advantage in the wet milling process is disclosed.

CROSS REFERENCE

This application is related to U.S. provisional application Ser. No.60/279,145 filed Mar. 27, 2001 and U.S. provisional application Ser. No.60/356,758 filed Feb. 15, 2002.

FIELD OF INVENTION

The present invention relates to the general fields of genetics, plantphysiology, grain composition, and specifically to the novel use ofwhite corn hybrids in the wet milling process. This application furtherrelates to novel white corn hybrids providing enhanced compositionalcharacteristics, increased yields of critical components usefull fornovel end-product uses, and potential for reducing processing wasteby-products in the wet milling process. The novel white corn productsprovide enhanced characteristics for feed applications, especially aquaculture.

BACKGROUND OF THE INVENTION

Corn (Zea mays L.) has a monoecious flowering habit. The male and femaleflowers are separate but develop on the same plant. The staminate (male)flowers are borne in the tassel and the pistillate (female) flowers areborne on the ears. Corn is predominantly cross-pollinated; pollen fromany tassel randomly pollinates the silks on the ears of adjacent plantsor even its own silks. The average corn tassel produces 25 millionpollen grains, and most ears have 500-1200 kernels.

The development of corn varieties in the early 1900s was dependent onmass selection. This technique involves no pollen control; each ear ispollinated by a random mixture of pollen from neighboring plants in thefield. Therefore, selection progress is slow. However, this technique iseffective for simply inherited characteristics, such as, ear and plantheight, ear number, adaptation, maturity, and kernel and earcharacteristics. Grain yield improvement by mass selection is moredifficult because random pollination involves both good and pooryielding plants. Also, the effects of genotype and environment cannot beseparated using mass selection techniques.

Alternatively, corn breeders employ controlled pollination, artificialselection and genetic analysis to develop numerous genetic lines orvarieties of corn displaying a plethora of desired traits, e.g., yieldpotential, maturity time, disease resistance, insect resistance, earsize, plant height, drought tolerance. Established inbred lines are usedas starting material for further crossing, selection, and analysis inorder to develop additional varieties. G. H. Shull (1909), of theCarnegie Institute, has been given credit for suggesting the developmentof pure inbred lines in corn. The method of inbred line developmentinvolves self-fertilization (selfing) of open-pollinated varieties andselection of homozygous biotypes. Inbred lines are generally notvigorous, and yields are low. Over time, breeders improve the eliteolder inbred lines through recycling. Also, new lines are developed fromsynthetics and populations improved by some form of recurrent selection.The resulting inbred lines from these sources have more vigor, tolerategreater stress by increased plant densities, and have increased yields.More specifically, plants that have been self-pollinated and selectedfor type for many generations become homozygous at almost all gene lociand produce a uniform population of true inbred breeding progeny. Across between two different homozygous inbred lines (single crosshybrid) produces a uniform population of hybrid plants that may beheterozygous for many gene loci.

Hybrid corn seed is typically produced by a male sterility systemincorporating manual or mechanical detasseling. Alternate strips of twocorn inbreds are planted in a field, and the pollen-bearing tassels areremoved from one of the inbreds (female). Providing that there issufficient isolation from sources of foreign corn pollen, the ears ofthe detasseled inbred will be fertilized only from the other inbred(male) and the resulting seed is therefore hybrid and will form hybridplants.

The laborious, and occasionally unreliable, detasseling process can beavoided by using cytoplasmic male-sterile (CMS) inbreds. Plants of a CMSinbred are male sterile as a result of factors resulting from thecytoplasmic, as opposed to the nuclear, genome. Thus, thischaracteristic is inherited exclusively through the female parent incorn plants, since only the female provides cytoplasm to the fertilizedseed. CMS plants are fertilized with pollen from another inbred that isnot male-sterile. Pollen from the second inbred may or may notcontribute genes that make the hybrid plants male-fertile. Seed fromdetasseled fertile corn and CMS produced seed of the same hybrid can beblended to insure that adequate pollen loads are available forfertilization when the hybrid plants are grown.

There are several methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 and chromosomal translocations as described inU.S. Pat. Nos. 3,861,709 and 3,710,511, the disclosures of which arespecifically incorporated herein by reference. There are many othermethods of conferring genetic male sterility in the art, each with itsown benefits and drawbacks. These methods use a variety of approachessuch as delivering into the plant a gene encoding a cytotoxic substanceassociated with a male tissue specific promoter or an antisense systemin which a gene critical to fertility is identified and an antisense tothat gene is inserted in the plant (EPO 89/3010153.8 and WO 90/08828).

Another system useful in controlling male sterility makes use ofgametocides. Gametocides are not a genetic system, but rather a topicalapplication of chemicals. These chemicals effect cells that are criticalto male fertility. The application of these chemicals effects fertilityin the plants only for the growing season in which the gametocide isapplied (see, U.S. Pat. No. 4,936,904 to Carlson, specificallyincorporated herein by reference). Application of the gametocide, timingof the application and genotype specificity often limit the usefulnessof the approach.

The use of male sterile inbreds is but one factor in the production ofcorn hybrids. The development of corn hybrids requires, in general, thedevelopment of homozygous inbred lines, the crossing of these lines, andthe evaluation of the crosses. Pedigree breeding and recurrent selectionbreeding methods are used to develop inbred lines from breedingpopulations. Breeding programs combine the genetic backgrounds from twoor more inbred lines or various other germplasm sources into breedingpools from which new inbred lines are developed by selfing and selectionof desired phenotypes. The new inbreds are crossed with other inbredlines and the hybrids from these crosses are evaluated to determinewhich of those have commercial potential. Plant breeding and hybriddevelopment are expensive and time-consuming processes.

Pedigree breeding starts with the crossing of two genotypes, each ofwhich may have one or more desirable characteristics that is lacking inthe other or which complements the other. If the two original parents donot provide all the desired characteristics, other sources can beincluded in the breeding population. In the pedigree method, superiorplants are selfed and selected in successive generations. In thesucceeding generations the heterozygous condition gives way tohomogeneous lines as a result of self-pollination and selection.Typically, in the pedigree method of breeding five or more generationsof selfing and selection is practiced: F₁ to F₂; F₂ to F₃; F₃ to F₄; F₄to F₅, etc.

In particular, a single cross hybrid results from the cross of twoinbred lines, each of which has a genotype that complements the genotypeof the other. The hybrid progeny of the first generation is designatedF₁ and exhibit hybrid vigor, or heterosis, in relation to their inbredparents. Hybrid vigor may be manifested in polygenic traits, such as,increased vegetative growth and increased yield. It is these hybridsthat are generally sought in commercial development. That is to say, anobjective for commercial corn hybrid development is to produce newinbred lines that combine to produce superior agronomic performance.

Typically, the development of a hybrid corn variety involves threesteps: 1) the selection of plants from various germplasm pools forinitial breeding crosses; 2) the selfing of the selected plants from thebreeding crosses for several generations to produce a series of inbredlines, which, although different from each other, breed true and arehighly uniform; and, 3) crossing the selected inbred lines withunrelated inbred lines to produce the hybrid progeny (F₁). Once created,a continual supply of hybrid seed can be produced using the inbredparents and the hybrid corn plants can be generated from the hybridseed.

A single cross hybrid is produced when two inbred lines are crossed toproduce the F₁ progeny. A double cross hybrid is produced from fourinbred lines crossed in pairs (A×B and C×D) and then the two F₁ hybridsare crossed again (A×B)×(C×D). Much of the hybrid vigor exhibited by F₁hybrids is lost in the next generation (F₂), and consequently, seed fromhybrids is not generally used for planting stock.

Hybrid seed production requires elimination or inactivation of pollenproduced by the female parent. Incomplete removal or inactivation of thepollen provides the potential for self-pollination. This inadvertentlyself-pollinated seed may be unintentionally harvested and packaged withhybrid seed. Once the seed is planted, it is possible to identify andselect these self-pollinated plants. These self-pollinated plants willbe genetically equivalent to the female inbred line used to produce thehybrid. Typically these self-pollinated plants can be identified andselected due to their decreased vigor. Female selfs are identified bytheir less vigorous appearance for vegetative and/or reproductivecharacteristics, including shorter plant height, small ear size, ear andkernel shape, cob color, or other characteristics.

Identification of these self-pollinated lines can also be accomplishedthrough molecular marker analyses. See, “The Identification of FemaleSelfs in Hybrid Maize: A Comparison Using Electrophoresis andMorphology”, Smith, J. S. C. and Wych, R. D., Seed Science andTechnology 14, pp. 1-8 (1995), the disclosure of which is expresslyincorporated herein by reference. Through these technologies, thehomozygosity of the self-pollinated line can be verified by analyzingallelic composition at various loci along the genome. Those methodsallow for rapid identification of the invention disclosed herein. Seealso, “Identification of Atypical Plants in Hybrid Maize Seed byPostcontrol and Electrophoresis” Sarca, V. et al., Probleme de GeneticaTeoritca si Aplicata Vol. 20 (1), p. 29-42.

Corn is an important field corp. Thus, a continuing goal of plantbreeders is to develop consistently performing, high-yielding cornhybrids that are agronomically sound and based on stable inbred lines.The reasons for this goal are obvious: to maximize the amount of grainproduced with the inputs used and minimize susceptibility of the crop toenvironmental stresses. While approximately 80% of today's corn crop isused to feed livestock, both in the United States and abroad, food andnon-food products containing corn number greater than 3500 and areincreasing. Corn is also a major source of product for the milling, bothdry and wet, industry. Principal products of dry milling include, forexample, grits, meal and flour. The principal products of wet millinginclude, for example, starch, fiber, corn syrup and dextrose. Corn oilrecovered from the corn germ is a by-product of both dry and wetmilling. Industrial and food applications of wet milling products ofcorn are based on the general functional and intrinsic properties ofcorn, such as viscosity, film formation, adhesive properties, taste,protein levels and starch types.

One of these milling products, starch, is comprised of two polymers(polysaccharides), amylose and amylopectin. In particular, starchderived from dent or flint corn is composed of approximately 73%amylopectin and 27% amylose, each of which does not exist free innature, but as a component of a discrete, semi-crystalline aggregate,called starch granules. Amylose is an essentially linear polymercomposed almost entirely of α-1-4 linked D-glucopyranose. Althoughtypically illustrated as a straight chain structure for the sake ofsimplicity, amylose is actually often helical. The interior of the helixcontains hydrogen atoms and is therefore hydrophobic, allowing amyloseto form a type of clathrate complex with free fatty acids, fatty acidcomponents of glycerides, some alcohols and iodine. Amylopectin, thepredominant molecule in most starches is a branched polymer that is muchlarger than amylose. Amylopectin is composed of α-1-4 linked glucosesegments connected by α-1-6 linked branch points.

Starch bearing plants, e.g., corn, produce different percentages ofamylose and amylopectin, different size starch granules and differentpolymeric weights for both the amylose and amylopectin. The ratio ofamylose to amylopectin within a given type of starch is an importantconsideration with respect to starch functionality in foods; differencesin ratios produce markedly different physical and functional propertiesin the starch. That is, amylose and amylopectin content and structureaffect the architecture of the starch granule, gelatinization andpasting profiles, as well as appearance and textural attributes.Heretofore, starch is typically physically and/or chemically treated tomanipulate these and other characteristics. For example, for manyindustrial purposes, the pearl starch fraction is treated with chemicalsto make the starch whiter.

Proteins, lipids, moisture and ash (minerals and salts) are also presentin starch granules in minute quantities. Starch granule proteins aredivided into two types on the basis of their ability to be extractedfrom the granules: surface and integral. Surface starch granule proteinsare extracted with salt solutions, whereas integral starch granuleproteins require more rigorous extraction, for example, with thedetergent sodium dodecyl sulfate (SDS) or an alkaline solution. Integralproteins are embedded and may be covalently bound in theamylose-amylopectin structure of the granule, while the surface proteinsare more loosely associated with the exterior of the granule. In orderto separately recover either or both starch or protein components, theprotein/starch matrix must be broken. In known processes for separatingprotein from starch, either steeping destroys the usefulness of proteinand starch or the protein is ineffectively recovered.

Typically, corn used for industrial or food purposes is either drymilled or wet milled. Historically, wet milling has been primarily usedto process yellow dent corn and the like. Traditionally, white cornvarieties are known for their inefficiency or inability to be wetmilled. Thus, the corn processing industry relies upon dry millingtechniques to process white corn.

The objective of the dry milling process is to remove the bran coat andgerm from the corn kernel while keeping the endosperm portion largelyintact, a process which, traditionally, has not or has not efficientlybeen accomplished using a wet milling process. This separation yieldsprime products high in starch, low in oil, essentially free of bran andgerm, and having excellent shelf life and stability. The dry millingprocess is comprised of several processing steps. Briefly, the incominggrain is cleaned and then moistened, or tempered, to loosen and toughenthe bran coat and soften the germ to facilitate separation in thedegerminator. The initial separation into the component parts begins inthe degerminator, a specially designed attrition mill containing atruncated cone, surfaced with numerous pearling knobs, rotating inside aperforated housing. As the tempered kernels pass through this device,the abrading action peels the bran coat and germ away from theendosperm. The germ, hull, and small endosperm pieces pass through theperforations in the housing (hereinafter referred to as “through stock”)and the larger endosperm pieces exit the end, or tail, of thedegerminator (hereinafter referred to as “tail stock”). The remainingsteps include aspiration, milling and sifting; and, drying and cooling.The end result is a spectrum of degermed corn products that includesflaking grits, corn flour, corn bran, corn oil and hominy feed. Thedegermed products are used in a wide variety of food and beverageapplications, some of which include breakfast foods, malt beverages,snack food, prepared mixes, batter and breading mixes and lowcalorie/high fiber foods.

The wet milling process is used primarily to extract starch and glutenfrom corn. Other fractions that are a part of the by-products includethe germ, fiber, and steep water. Generally, wet milling involves aninitial water soak under controlled conditions to soften the cornkernels. The corn is then milled and its components separated byscreening, centrifuging and washing. The first step in the actualprocessing is called steeping and includes controlled processingconditions such as temperature, time, and sulfur dioxide concentration.Steeping softens the kernels, facilitating separation of the corncomponents. The corn kernels are placed in a steeping tank with acountercurrent flow of water at about 120-125° F. The water is treatedwith sulfur dioxide (SO₂) to a concentration of 0.12-0.20% by weight.The sulfur dioxide increases the rate of water diffusion into the kerneland assists in breaking down the protein-starch matrix necessary forhigh starch yield and quality. The kernels remain in the steep tank for24-50 hours. In general, 8-9 gallons of water/bushel of corn isrequired, with about 3.5 gallons/bushel being absorbed by the corn toincrease its moisture from approximately 16% to 45% during steeping. Theremainder, approximately 4.5-5.5 gallons/bushel, is removed from thesystem and must be dealt with in an environmentally acceptable manner.The kernels are then dewatered, and subjected to sets of attrition typemills to release the germ.

After the germ is recovered, the remaining kernel components includingthe starch, hull, fiber, and gluten are subjected to another set ofattrition mills and passed through a set of wash screens to separate thefiber components from the starch and gluten. The starch and gluten passthrough the screens while the fiber does not. Centrifugation or a thirdgrind followed by centrifugation is used to separate the starch from theprotein. Centrifugation produces a slurry which contains the starchgranules which is dewatered, washed with fresh water, and dried to about12% moisture. The amount of extractable starch has been one of the primeconcerns of wet millers. It is dependent upon the ease of separation ofthe components, uniformity of the product, and the hardness of theendosperm. Yellow corn generally has a relatively hard endosperm,requiring a higher level of sulfur dioxide in the steeping process toseparate the components. More sulfur dioxide results in more wasteby-products requiring disposal.

Traditionally, the dry and wet milling industries have not selected cornhybrids for milling based on particular component profile of the hybridkernels, for example, protein characteristic of the endosperm, an aminoacid characteristic, a β-carotene characteristic, a xanthophyllcharacteristic, a starch characteristic, and combinations thereof. Infact, it is a common practice in the milling industry to mix togetherdifferent corn varieties prior to milling in order to obtain moreuniform end-products.

There is a need, therefore, to select white corn hybrids for wet millingbased on particular grain components, for example, proteincharacteristic of the endosperm, an amino acid characteristic, aβ-carotene characteristic, a xanthophyll characteristic, a starchcharacteristic, and combinations thereof. There is also a need to selectparticular white corn hybrids adapted for wet milling and potentiallyrequiring the use of less steeping water and sulfur dioxide during thewet milling process. A further need is for an improved wet millingprocess for efficiently processing white corn hybrids.

Both environment and genetics affect the properties of corn for alkalinecooking. See, Bedolla, S. 1980, “Effect of genotype on cooking andtexture of corn for tortilla production”, M.S. thesis, Texas A&MUniversity, College Station. See also, Goldstein, T. M. 1983, “Effect ofenvironment and genotype on hardness and alkaline cooking properties ofmaize”, M.S. thesis, Texas A&M University, College Station. In general,the properties desired in corn for alkaline cooking are: uniformly sizedkernels of high density and high test weight. A high proportion of hardor flinty endosperm, intact kernels free of fissures or stress cracks,kernels without prominent dents in the crown, easily removed pericarp,clean yellow or white color, and white cobs instead of red.

Rate of cooking is affected by the relative rate of water and alkaliuptake by the corn kernels. Improper drying and handling of corn causesfissuring and breakage, which causes overcooking. Soft kernels, brokenkernels, or kernels with fissures take up water and alkali more quicklyand cook faster. Thus, some kernels are overcooked and may dissolveduring handling, which increases dry matter losses, and produces masawith poor properties.

A properly cooked corn kernel consists of enough gelatinized, swollenstarch granules and hydrated protein matrix to produce a dough when itis stone-ground. The attrition of the stone disrupts the swollen starchgranules and hydrated protein and causes dough formation. The amylose,amylopectin, and protein form a continuous system, i.e., “glue” thatholds the ungelatinized starch and intact endosperm cells together in acohesive dough. Overcooked corn often forms masa with a stickyconsistency because too much glue is formed. The complex interactionbetween amylose, amylopectin, proteins, ungelatinized starch granules,and endosperm particles is not understood. More information on thiscomplex could lead to many practical applications.

SUMMARY OF THE INVENTION

The invention described herein relates to novel white corn hybridsspecifically selected for wet milling, and includes novel white cornhybrids that provide enhanced compositional characteristics andincreased yields of critical components useful for novel end-productuses, and potential for reduced processing waste by-products in the wetmilling process.

The present invention includes hybrid varieties of white corn havingnovel wet milling processing characteristics and novel feed value. Thehybrids disclosed herein include the preferred embodiments of white cornhaving enhanced compositional characteristics, for example 1851W andE8272, and are of the genus species Zea mays L. These hybrids are bredand selected to yield improved and/or enhanced levels of one or moregrain components, and to be effectively and efficiently wet milled.

The present invention further includes selecting hybrid varieties ofwhite corn for wet milling based on particular grain components, forexample, protein characteristic of the endosperm, an amino acidcharacteristic, a β-carotene characteristic, a xanthophyllcharacteristic, a starch characteristic, and combinations thereof.

The invention further includes an improved wet milling process, wherebythe hybrids of the invention are easily separated into their componentsusing an improved wet milling process that potentially increases plantefficiency in terms of quantity of product run verses time of operation.

The hybrids of the invention are further developed to yield elevatedlevels of one or more amino acids, for example, proline, pursuant toprocessing.

The invention also includes obtaining an essentially pure, very white,natural starch having improved functional properties that does notrequire chemical modification to achieve such whiteness. The inventionincludes selecting white corn hybrids that yield in the wet millingprocess a high protein, nearly carotene-free gluten meal.

The invention further includes an improved method of wet milling inorder to extract and separate the grain components of white cornhybrids.

The invention further includes the identification of a unique starchcomplex that significantly effects steep time, cook time, cooktemperature, and waste reduction in the alkaline cooking process oftortillas.

The invention further includes the development of a model for tortillaproduction that can be used as a screening tool by plant breeders.

Other features and advantages of the present invention will becomeapparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the differential scanning calorimetry (DSC) profile for the1851W starch.

FIG. 2 illustrates an electron microgroup of the small, round granulesfound in the tip area of the 1851W kernel.

FIG. 3 is an electron micrograph of the crown section of 1851W kernel.

FIG. 4 is a chromatographic profile of the amylose and amylopectin of1851W starch.

DEFINITIONS

The following definitions are helpful in understanding the specificationand claims. The definitions provided herein should be borne in mind whenthese terms are used in the following examples and throughout theinstant application.

ADVANTAGE is the advantage a hybrid has compared to another hybrid foryield (bushels per acre), moisture content, income, population, stand,roots, and test weight.

ALEURONE COLOR is the color of the aleurone scored as white, pink, tan,brown, bronze, red, purple, pale purple, colorless or variegated.

AMYLOPECTIN STARCH averages about 70-75% of the total corn starchderived from yellow corn seed and is a branch molecule with alpha-(1,6)linked branch points and linear regions of alpha-(1,4) linked glucoseunits.

AMYLOSE STARCH averages about 25-30% of the total corn starch, and is anessentially linear molecule of glucose units linked together.

BUSHELS PER ACRE (BU ACR) is the actual yield of the grain at harvestadjusted to 15.5% moisture. ABS is in absolute terms and % MN is percentof the mean for the experiments in which the hybrid was grown.

COB COLOR is the color of the cob, scored as white, pink, red or brown.

COMMON RUST (Puccinia sorghi) is a 1 to 9 visual rating indicating theresistance to Common Rust. A higher score indicates a higher resistance.

CORN PLANT PARTS means cells, protoplasts, tissue cultures from whichcorn plants can be regenerated, calli, plant clumps, embryos, pollen,flowers, kernels, ears, cobs, leaves, husks, stalks, roots, root tips,anthers, silk and other intact organs or tissues of a corn plant.

CROWN RATING: 1-8 (8=very small crown).

DENT RATING: 1-8 (8=no dent).

DIFFERENTIAL SCANNING CALORIMETER allows the direct measurement of theenergy required to gelatinize starch.

DRYDOWN (D/D) is a relative rate at which a hybrid will reach acceptableharvest moisture compared to other hybrids on a 1-9 rating scale. A lowscore indicates a hybrid that dries relatively fast while a high scoreindicates a hybrid that dries slowly.

DROUGHT TOLERANCE (D/T) refers to a 1-9 rating for drought tolerance andis based on data obtained under stress conditions. A low score indicatesgood drought tolerance and a high score indicates poor droughttolerance.

EAR HEIGHT (EAR HT) refers to ear height as measured from the ground tothe top developed ear node attachment and is measured in inches.

EAR HEIGHT RATING (E/HT/R) is a 1-9 rating with a 1, 5 and 9representing a very low, average and very high ear placement,respectively.

EAR FLEX refers to ear size in response to plant populations. Adeterminate ear size means that the ear length remains fairly constantover a wide population range. A flex ear will change in length or girthin response to different plant populations.

EAR TYPE refers to the ability of the ear to flex and is classified asFixed (determinate ear size), Flex (indeterminate ear size), orSemi-Flex.

EMERGENCE is the rating of growth to the 2^(nd) collared leaf (V2)stage, 1=excellent.

ENDOSPERM COLOR is the color of the endosperm scored as white, paleyellow or yellow.

ENDOSPERM TYPE is the type of endosperm scored as normal, way or opaque.

GDD is the number of growing degree days or heat units required for aninbred line or hybrid to reach anthesis or pollen shed from the time ofplanting. For each hybrid, it takes a certain number of GDDs to reachvarious stages of plant development. GDDs are a way of measuring plantmaturity.

GDU=Growing Degree Unit.

GDU TO PHYSIOLOGICAL MATURITY is the number of growing degree unitsrequired for an inbred or hybrid line to have approximately 50% ofplants at physiological maturity from time of planting.

GDU TO POLLEN is the number of growing degree units required for aninbred or hybrid line to have approximately 50% pollen shed from thetime of planting.

GDU TO SILK is the number of growing degree units required for an inbredline or hybrid to have approximately 50% of the plants with silkemergence from time of planting.

GRAIN comprises mature corn kernels produced by commercial growers forpurposes other than growing or reproducing other species.

GRAIN COLOR is the color of the grain scored as white, yellow, orange,red, purple or brown. Color differences may be due to geneticdifferences in pericarp, aleurone, germ, and endosperm.

GRAY LEAF SPOT (Cercospora zeae) disease rating is scored visually on ascale of 1 to 9, with 9 indicating the highest disease resistance.

HARD/HORNEOUS ENDOSPERM (%): visual evaluation according to guidelinesdeveloped by Quaker Oats.

HIGH PERFORMANCE SIZE EXCLUSION CHROMATOGRAPHY (HPSEC) of starch allowsfor the determination of degree depolymerization (from shear, enzymes orother causes) during processing of starch and starch-based ingredientsor foods.

HYBRID refers to the progeny of a cross fertilization between parentsbelonging to different genotypes, or the first generation offspring of across between two homozygous individuals differing in one or more genes.

KERNEL is the corn caryopsis comprising a mature embryo and endospermwhich are products of double fertilization.

KERNEL DENSITY is determined by pre-weighing 100 kernels and placingthem in a Micromeritics helium-air comparison pycnometer which measuresvolume in cubic centimeters. Kernel density is calculated as mass of the100 kernels divided by their volume.

KERNEL ROWS is the average total number of kernel rows on the ear. Ifthe rows are indistinct, this value is the average number of kernelslocated around the circumference of the ear at the mid-point of itslength.

LATE SEASON INTACTNESS: ability to maintain plant integrity orintactness prior to harvest, 1=excellent.

MASA is the corn-based dough used inproducing corn chips and corn-basedtortillas and tortilla chips.

MATURITY TO SILK is the maturity time from planting to 50% of plants insilk and is measured in days and heat units.

MATURITY TO POLLEN is the maturity time from planting to 50% of plantsin pollen and is measured in days and heat units.

NIXTAMALIZATION is the process of taking dry corn and lime and combiningthem in a kettle with water that is heated to near boiling temperatures.

NORTHERN LEAF BLIGHT (Exserohilum turcicum) disease rating is scoredvisually on a scale of 1 to 9, with 9 indicating the highest diseaseresistance.

NUMBER OF EARS is the average number of ears per plant.

OIL (%) is the amount of the kernel that is oil, expressed as apercentage on a dry weight basis.

PERICARP COLOR is the color of the pericarp scored as colorless, orange,cherry red, red-purple, purple or brown.

PLANT COLOR is the color of the plant scored as very light green,moderate green or very dark green.

PLANT HEIGHT is measured from the ground to the tip of the tassel, andis measured in inches.

PROTEIN (%) is the amount of the kernel that is crude protein, expressedas a percentage on a dry weight basis.

RAPID VISCO-ANALYZER (RVA) is a means to measure the change in viscosityof starch under low shear rates when the temperature is increased to 95degrees C.

RELATIVE MATURITY is a maturity rating based on regression analysis. Theregression analysis is developed by utilizing check hybrids and theirpreviously established day rating versus actual harvest moistures.Harvest moisture on the hybrid in question is determined and thatmoisture value is inserted into the regression equation to yield arelative maturity.

RESPONSE TO LOW DENSITY: ability of a hybrid to respond to plantpopulations below 25,000 plants/acre, 1=excellent.

RESPONSE TO HIGH DENSITY: ability of a hybrid to respond to plantpopulations ranging from 25,000 to 30,000 plants/acre, 1=excellent.

ROOT STRENGTH refer to a 1-9 rating measurement of the ability of aplant to resist lodging or leaning more than 45 degrees, where 1, 5 and9 represent outstanding, good and poor, respectively.

SEED refers to mature corn kernels produced for the purpose ofpropagating the species.

SEEDLING GROWTH: rating of growth from V2-V5 stage, 1=excellent.

SHANK LENGTH refers to a measurement rating of the length of the earshank usually classified as short, medium, or long.

SOUTHERN LEAF BLIGHT (Bipolar maydis) disease rating is scored visuallyon a scale of 1 to 9, with 9 indicating the highest disease resistance.

STALK STRENGTH refers to a 1-9 measurement rating of the ability of theplant to resist stalk breakage below the node where the ear is attached,where 1, 5 and 9 represent outstanding, good and poor, respectively.

STARCH (%) is the amount of the kernel that is starch, expressed as apercentage on a dry weight basis.

STARCH BLEEDING (%): percent of kernels demonstrating starch bleedingaround the embryo.

STAYGREEN is the ability of the plant to maintain photosynthesis in theleaves and stalks through drydown, 1=excellent.

STEWART'S WILT (swilt; Erwinia stewartii) disease rating is scoredvisually on a scale of 1 to 9, with 9 indicating the highest diseaseresistance.

THINS (%): percent of kernels passing through a 20/64″ round holescreen.

100 KERNEL WEIGHT is a weight measurement of 100 randomly selectedkernels that is averaged to estimate relative kernel size.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by on of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar or equivalent to those described herein can be used to practicethe invention, suitable methods and material are described below. Allpublications, patent application, patents, and other referencesmentioned herein are incorporated by reference in their entirety. Incase of conflict, the present specification, including definitions, willcontrol. In addition, the materials, methods and example areillustrative only and not intended to be limiting.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention as claimed.

A small quantity of white corn has traditionally been wet milled withdifficulty to produce specialty products with very bright whiteness. Tobe economically feasible, the value of the resultant specialty starchhas yet to overcome the production premiums of time and expense as whitecorn is known not to wet mill efficiently. Contrary to expectations, thewhite corn hybrids of the instant invention may be effectively andefficiently wet milled, and in fact, perform superiorly to yellow dentcorn with standard wet milling techniques. That is, the components ofthe white corn hybrids are easily separated with standard wet millingtechniques, and may also be processed more efficiently with improved wetmilling techniques.

A representative embodiment of the instant invention includes WilsonGenetics white corn hybrids 1851W and E8272 showing consistent kernelcharacteristics and grain component yields subject to wet milling. Thesepreferred hybrids further exhibit superior quality components, and areparticularly well-suited for novel methods of wet milling.

Wilson Genetics hybrids 1851W and E8272 are single cross hybrids thatare related by a common female parent. Both hybrids have a male parentthat was derived from tropical germplasm. A comparison of their traitsare summarized as follows: TABLE 1 EXEMPLARY HYBRID DESCRIPTIONINFORMATION FOR HYBRIDS 1851W and E8272 Traits 1851W E8272 Female ParentWEBF428C WEBF428C Male Parent WICY226C WICY418C Relative Maturity (Days) 116-118  115-117 GDU to Silk 1499-1538 1499-1538 GDU to Pollen1499-1538 1499-1538 GDU to Physiological Maturity 3175-3198 3150-3198Plant Characteristics: Plant Height (inches)  100-104  98-102 Ear Height(inches)  50-56  50-56 Shank Length Medium Medium Kernel Rows 16  14-16Plant Color Dark Green Dark Green Grain Color White White Cob ColorWhite White Ear Type Long, Girthy Long, Slender Ear Flex Excellent (2.0)Excellent (2.0) Number of Ears/Stalk  1 1 Emergence Very Good (3.0) VeryGood (3.0) Seedling Growth Very Good (4.0) Very Good (3.0) Late SeasonIntactness Excellent (2.0) Good (5.0) Staygreen Excellent (2.0) VeryGood (4.0) Drydown Good (5.0) Very Good (4.0) Stalk Strength Excellent(2.0) Very Good (4.0) Root Strength Good (5.0) Good (5.0) DroughtTolerance Excellent (2.0) Excellent (2.0) Response to Low PopulationExcellent (2.0) Excellent (2.0) Response to High Population Very Good(3.0) Very Good (4.0) Grain Characteristics Pericarp Color White WhiteAleurone Color White White Endosperm Color White White Endosperm TypeHard Hard Horneous Endosperm (%)   85-90   85-90 100 Kernel Wt.(grams) - unsized  38.3-41.0  34.0-38.0 Protein (%) - dry weight basis  9.0-11.0   9.0-10.0 Oil (%) - dry weight basis   4.2-4.9   3.8-4.4Kernel Density (g/cc)  1.31-1.34  1.30-1.31 Thins (% thru a 20/64″screen)   5.0-10.0  10.0-15.0 Crown Rating  6.5 6.0 Dent Rating  7.0 6.5Disease Resistance Northern Leaf Blight Excellent (1.0) Excellent (1.0)Southern Corn Leaf Blight Excellent (2.0) Excellent (2.0) Gray Leaf SpotExcellent (1.0) Excellent (1.0) Common Rust Average (6.0) Very Good(3.0) Steward's Bacterial Wilt Excellent (2.0) Average (6.0)

This invention includes hybrid white corn seeds, including those of1851W and E8272, the hybrid corn plants produced from the hybrid cornseeds, and variants, mutants and modifications of 1851W and/or E8272 andsimilarly classified and characterized hybrids. This invention may alsorelate to the use of such hybrids in producing other hybrids, e.g.,three-way or double cross hybrids. The terms variant, trivialmodification and mutant refer to a hybrid seed where a plant produced bythat hybrid seed is phenotypically similar to, for example, the 1851Wand E8272 hybrids. As used herein, the term “plant” includes plantcells, plant protoplast, plant cell or tissue culture from which a cornplant can be regenerated, plant calli, plant clumps and plant cells thatare intact in plants or parts of plants, such as flowers, kernels, ears,cobs, leaves, husks, stalks and the like.

The inbred parents of the illustrative hybrid 1851W include a tropical,and preferably, male parent WICY226C, and a domestic, and preferably,female parent WEBF428C. The inbred parents of the illustrative hybridE8272 include a tropical, and preferably, male parent WICY418C, and adomestic, and preferably, female parent WEBF428C. The tropical inbredparents are selected for grain characteristics such as hardness, diseaseresistance and diversity, but show good yield when crossed with U.S.derived stiff stalks. As used herein, the term “tropical” refers togermplasm originally collected from regions outside of the UnitedStates. The hybrids are selected from various inbred crosses based uponone or more grain characteristics, e.g., color (bright white), yield,kernel hardness, cap smoothness, kernel size and shape uniformity, theprotein characteristics of the endosperm, the character of the starch,combinations of these and the like.

The inbred parents as well as the exemplary F₁ hybrid crosses resultingtherefrom disclosed herein have been deposited in accordance with MPEP §608.01(p) and 37 C.F.R. §§ 1.801-1.809, with the American Type CultureCollection, 10801 University Blvd., Manassass, Va., 20110-2209 andassigned ATCC accession numbers: PTA-2921 for WICY226C; PTA-2924 forWEBF428C; PTA-2923 for 1851W; PTA-2925 for WICY418C; and, PTA-2922 forE8272.

Contrary to the expectation that white corn performs poorly, if at all,in wet milling applications, the instant hybrids exhibit superiorperformance with standard wet milling methods, and potentially, as wellwith the novel methodology disclosed herein. More specifically, thegrain components of the instant hybrids (starch, fiber, protein, andembryo) separate cleaner and easier than other white corn, and as wellas many varieties of yellow dent corn, resulting in purer extractedproducts and higher milling capacity.

The instant invention provides novel corn gluten meal, novel feedingredient use of the corn gluten meal, novel starch, and use of whitecorn to advantage in the wet milling process, not previously known.Extraction of corn gluten meal and starch from corn plants is well knownand typically involves a wet milling process. In accordance with thepresent invention, a wet milling process is used to advantage to extractthe corn starch and protein from the corn kernels. The extracted starchis processed as described infra; the protein extracted is processed inmanners consistent with those which are well known in the art.Conventional wet milling is comprised of the steps of steeping, grindingthe corn kernel and separating the components of the kernel. Prior tosteeping, the kernels are subjected to a cleaning process to remove anydebris that may be present. This cleaning process is usually performedat the wet milling plant. The kernels are then steeped in a steep tankwhere they are contacted with a countercurrent flow of water at anelevated temperature, approximately 120° F., the water containing sulfurdioxide at a concentration of approximately 0.2% by weight. The kernelsremain in the steep tank for approximately 24-48 hours. The kernels arethen dewatered and subjected to various sets of attrition type mills.

In wet milling processes, a first set of attrition type mills generallygrind and rupture the kernels releasing the germ from the kernel. Acommercial attrition type mill suitable for the wet milling is availableunder the brand name Bauer. (Andritz Incorporated, Muncy, Pa.).Centrifugation separates the released germ from the rest of the kernel.A typical commercial centrifugation separator is the Merco CentrifugalSeparator. (Alpha Laval Separations, Inc., Warminisder, Pa.). Throughoutthe grinding steps, the kernel and the kernel components are maintainedin a slurry of approximately 40% by weight solids.

Next, the remaining kernel components, including the starch, hull,fiber, and gluten, are subjected to another set of attrition mills tofurther grind the components and separate the hull and fiber from thestarch and gluten, and then passed through a set of wash screens toseparate the fiber components from the starch and gluten. The starch andgluten pass through the screens. The fiber component does not passthrough. Centrifugation, or alternatively, a third grind followed bycentrifugation, is used to separate the starch from the protein.Centrifugation produces a starch granule containing slurry that isdewatered, washed with fresh water and dried to approximately 12%moisture. The substantially pure starch of the present invention isextracted from the white corn grain in the above-described manner.

Typical yields of starch and gluten from the processes disclosed hereinwith yellow dent corn grain fall within the range of 65-67% d.b. and4.6-5% d.b. for starch and gluten, respectively. The amounts obtainedfrom the process of milling the hybrids of the instant invention areapproximately 70% d.b. and 6-7% d.b., respectively, demonstrating thatthe wet milling of the instant hybrids results in higher yield of starchand gluten. The gluten recovered from wet milling with respect to thepresent invention contains significantly more protein (77-82%) thangluten recovered from yellow dent corn (60-66%). Furthermore, analysisof the gluten fraction recovered from wet milling demonstrates thatgluten from yellow dent corn contains 22-23% starch, while the glutenfrom the present invention contains less than 9% starch, clearlyindicating a distinct improvement in the protein, starch separation withthe present invention; that starch having percentages of amylose andamylopectin ranging from 11-17% and 80-86%, respectively. Moreover,overall milling efficiency, compared to yellow dent, is improved inprocessing the hybrids of the instant invention based upon a combinationof increased speed of separation of protein and starch, improved starchand gluten yields and potentially less chemical usage

Preferably, to preserve the desirable characteristics of end productsresulting from the present invention wet milling of selected hybrids ofthe invention are carried out on an identity preserved basis. As usedherein, “identity preserved basis” means that at least about 70%,preferably at least 90%, and more preferably at least 99%, of the whitecorn that is milled in a milling run is derived from a single hybrid ofthe present invention. That is, a novel processing methodology preservesspecial characteristics based upon the absence of grain comminglingduring milling. Hence, the hybrid maintains its identity from the timeof planting through harvesting, storage, and delivery to the processingplant. Preferably, the minimum purity standard that is used is 98%.Heretofore, commingling of grain has been a predominant wet millingmethodology employed in the industry, effectively “averaging” theadvantages and disadvantages of myriad corn varieties.

White corn hybrids of the present invention may be selected for wetmilling based upon one or more selection criteria by which these hybridsmay be identified and used to provide the advantages discussed herein.In particular, these selection criteria may include: gluten and starchyields; quality and/or level of endosperm protein; protein solubility;levels of xanthophyll (preferably the substantial lack thereof); levelsof β-carotene (preferably the substantial lack thereof); proteindigestibility; and amino acid characteristics (e.g., increased prolinecontent). By way of further example, additional hybrid selectioncriteria may include unique characteristics of their starch component,such as, viscosity, retrogradation and thermal peaks.

The 1851W hybrid is exemplary with respect to these selection criteria.Some of the specific advantages of the 1851W hybrid include, e.g., lowerstarch levels in gluten, elevated amino acid levels, increased proteinyield derived from hard endosperm, reduced pigmentation component levelsand increased solubility. Corn gluten components are generally comprisedof 20-23% starch, while the gluten of these hybrids contains less than9% starch. A higher level of selected desirable amino acids is foundwithin the approximately 80% protein yield. For example, in addition toa detectably elevated proline level in 1851W, the levels of xanthophylland β-carotene are extremely low. The solubility of proteins in water isincreased 6-fold; the elevated solubility of fiber and protein (72%versus 30-35%) enhances the digestibility. The increased digestibilityis attributable to the increased protein level, rather than theinsoluble complex components (hemocellulose) of the cell wall. Thestarch of the 1851W hybrid also resists gelatinization. The improvedstarch of the hybrids disclosed herein is natural but carriescharacteristics of a modified starch as discussed infra. The uniqueproperty of the 1851W starch includes its ability to remain viscous andresist gelling longer than other corn varieties. This is advantageous inthe food industry.

The E8272 hybrid is similar to 1851W with respect to the selectioncriteria for wet milling products and co-products. Some of the specificadvantages of the E8272 hybrid include, e.g., bright white grain andendosperm color, uniform kernel size, above average protein and oil, lowash content, excellent density, and low levels of xanthophyll andbeta-carotene.

The starch obtained from the hybrids of the instant invention generallyalso possess advantages over the starch obtained from typical yellowdent corn. Typically, yellow cornstarch from wet milling is subject toany one or more of eight general treatments to make it suitable for avariety of end-uses. These treatments include, for example, bleaching,thin boiling, acid treatment, enzyme treatment, dextrinization ordryroasting, etherification, esterification, and crosslinking. Starchestreated by one or more of these treatments are commonly referred to aschemically modified starch. Bleaching (or oxidation) lightens the colorof the starch granules and is normally necessary to make corn starchsuitable for use in laundry starch, paper coating, textile size and as afood ingredient, but tends to reduce the viscosity of the starch pasteproduced therefrom.

In contrast, the pure white starch of the present invention requires nobleaching thus saving the wet miller the cost of this normally requiredmodification process. Further, the preservation of the viscosity,normally lost by the bleaching process, increases the water holdingcapacity of the starch of the present invention, thereby providingcrosslinking sites to produce stabilized starches resistant to acid andshear, useful in adhesives and coatings, and may be useful in proteininteractions in food and pharmaceuticals. This unique starch, due to itsenhanced crosslinking, is useful for wastewater treatment and metalrecovery based upon its enhanced electrolyte binding capability.Moreover, this starch has enhanced capability of providing sites forattachment of other polymers, thus, eliminating one step in producingamphoteric starch. The present invention has significant advantage foruse in the food ingredient business. This starch is naturally occurringin this variety, eliminating the need for chemical modification andminimizing FDA regulatory approval.

Starches are often modified by numerous techniques known in the industryto change the behavioral characteristics of the starch, yet stillessentially retain the caloric value of the native or unmodified starch.One type of modification is crosslinking. When an aqueous dispersion ofnative starch is heated, the starch granules begin to swell, and thedispersion develops a short, salve-like texture that is essential inimparting palatability and in thickening food systems. However, duringthe process of cooking the native starch, this textural state rapidlychanges to an elastic, rubbery state when the swollen granules rupture.Minor variations in cooking time, temperature and concentration as wellas shear and pH are sufficient to effect this transformation.Crosslinking modifications act to strengthen the granules by reinforcingthe hydrogen bonds that are responsible for holding the granules intactand these are used to overcome the extreme sensitivity of the swollenstarch granules to handling and processing conditions.

Aqueous dispersions of crosslinked starch are often used underconditions involving prolonged storage at relatively low temperaturesand/or exposure, at times, to repeated freezing and thawing cycles.Under such circumstances involving exposure to low temperature, there isa distinct loss in the hydrating power of the starch that is present infood products, thereby resulting in syneresis, an exudation of liquid,together with a marked deterioration in the texture, color and clarityof the product. Attempts to overcome these difficulties have involvedthe introduction of substituted branches onto the starch molecule bymeans of various chemical derivatization reactions, for example,reacting the starch with a monofunctional reagent to introducesubstituent such as hydroxypropyl, phosphate, acetate or succinategroups. Such substituents stabilize the starch by interfering with theassociation between molecules or portions of the same molecule, thusreducing the tendency of the substituted starches to lose theirhydration ability and clarity upon storage, particularly at lowtemperatures. These derivatization reactions may be carried out alone,but are frequently employed in combination with crosslinking.

Alkali Cooking Basics

Masa is the corn-based dough that forms the base for corn chips,corn-based tortillas, and tortilla chips. Alkali processors produce masaby cooking corn in the presence of lime (calcium oxide) in a processknown as “nixtamalization.”

Nixtamalization begins by combining dry corn and lime in a kettle ofwater and cooking the mass with steam injection to near boiling.Depending on the product being made, the cooking time will vary.Tortilla chips require between 5 and 10 minutes of cooking, while cornchips require 20 to 30 minutes. Even longer cooking times are necessaryfor tortillas.

Some processors stop the cooking process by quenching the corn with coldwater. Others simply drain the corn. Either way, the corn next muststeep in tanks for 8 to 12 hours. Because the cooking step typicallyonly partially cooks the kernels, steeping is necessary to allowmoisture and lime to be distributed evenly.

After steeping, the corn is ground to form masa. Next, the masa isformed and fried to make corn chips; formed and baked to createtortillas; or formed, baked, cut and fried for tortilla chips.

Several variables affect the results of nixtamalization including cornhardness, lime concentration, cooking time and temperature, steep timeand temperature, degree of cooking, and the final moisture content.Although nixtamalization has a long history, recreating the process onan industrial scale presents several challenges.

First, heating huge tanks of water and corn for cooking requires a greatdeal of energy. The steep time also is very critical. If the steep istoo short, the kernels will have hard areas that are difficult to grind.The resulting masa also may tend to be dry and crumbly. Steeping for toolong yields a sticky masa that is difficult to sheet for furtherprocessing.

Another challenge is that the cooking-steeping part of creatingmasa-based products is done batchwise, while the remainder iscontinuous. If something goes wrong with cooking or steeping, the restof the line will experience costly downtime. If a mechanical breakdownoccurs on the continuous part of the process, the time-sensitive cookingand steeping processes may generate waste while the problem iscorrected.

From cooking to forming and finishing corn-based products, dry matterloss (DML) is an ongoing battle. In fact, some manufacturers experiencedry matter losses as high as 8% to 17%. Even the most diligent ofcompanies may experience yield-robbing DMLs because the corn itself canbe a contributing factor.

EXAMPLE 1

This example illustrates the extraction of the substantially pure starchof the present invention from white corn hybrid line 1851W and analyzesthe individual components to determine various characteristics. Theextraction and analysis of the starch, gluten and fiber components fromthe present invention (1851W) is summarized in Table 2. Also included inTable 2 is a comparison of the grain analysis of the present invention(1851W) to that of yellow dent corn. The improved variety of the corn ofthe instant invention, an F₁ hybrid, produces grain with higher protein,and extremely low levels of carotenoids. It is also important to notethat the 1851W gluten and fiber components have substantially higherprotein levels than the yellow corn. In addition, the fiber portion of1851W has significantly higher protein solubility values than the yellowcorn. The extraction process is outlined in a flow diagram in FIG. 1.Analysis of the components presented in Table 2 were completed accordingto standard procedures used by the Experiment Station ChemicalLaboratories, University of Missouri—Columbia, Columbia, Mo., inaccordance with AOAC standards. TABLE 2 Wet Milling Comparison of 1851Wvs. Standard Yellow Hybrid Yellow Yellow Yellow 1851W Corn 1851W Corn1851W Corn 1851W 1664 Trait Gluten Gluten Fiber Fiber Starch StarchGrain Grain Crude Protein (%)* 77.46 71.90 19.3 10.40 0.31 0.26 9.868.81 Crude Fat (%)* 1.04 1.38 1.91 47.12 0.00 0.08 4.49 4.21 Crude Fiber(%)* 0.68 0.85 7.62 6.04 0.07 0.27 2.34 2.05 Ash (%)* 2.22 3.35 5.400.87 0.09 0.21 1.26 1.45 ADF (%)* 2.30 0.96 10.01 22.43 0.06 0.02 3.642.90 NDF (%)* 2.82 1.65 44.94 39.39 0.43 0.31 13.24 11.35 Cellulose (%)*2.15 1.93 9.45 17.47 0.03 0.06 2.73 2.65 Phosphorus (%)* 0.58 0.91 0.990.24 <0.06 <0.05 0.26 0.31 Starch (%)* 9.93 10.53 28.93 10.41 96.2898.25 64.67 71.73 Protein Solubility (%)* 9.25 8.22 6.84 1.22 <0.40 <0.40.95 <0.40 Beta Carotene (ug/100 g) 104.00 345.0 202.00 91.0 <0.05 <0.05<0.05 107.5 Xanthophyll (ug/100 g) 50.20 1804.0 89.70 0.22 <0.08 <0.08<0.08 4.08 Fatty Acids (% of total fat): Myristic (14:0) 0.00 0.00 0.090.03 0.00 0.00 0.03 0.00 Myristoleic (14:1) 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 Palmitic (16:1) 11.98 14.17 13.66 10.14 27.87 27.39 11.6813.14 Palmitoleic (16:1) 0.27 0.18 0.00 0.09 0.00 0.00 0.13 0.12 (17:0)0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Stearic (18.0) 2.16 1.86 2.351.91 2.63 2.36 1.93 1.94 Oleic (18:1) 21.29 21.81 22.51 26.71 10.8412.06 22.43 23.77 Linoleic (18:2) 57.80 55.02 57.45 58.04 44.81 42.4159.42 56.42 Linolenic (18:3) 2.44 2.60 2.99 0.89 2.11 2.86 1.06 1.80(w18:4) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Arachidic (20:0) 0.350.35 0.37 0.55 0.00 0.00 0.46 0.45 Arachidonic (20:4) 0.00 0.00 0.000.00 0.00 0.00 0.00 0.00 (w20:5) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Docosanoic (22:0) 0.35 0.25 0.26 0.29 0.00 0.00 0.27 0.27 Erucic (22:1)0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 (w22:6) 0.00 0.00 0.00 0.00 0.000.00 0.00 0.00 Lignoceric (24:0) 0.25 0.23 0.14 0.21 0.00 0.00 0.20 0.19(w24:1) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00Values are based on a 0% moisture basis

Illustrative yield comparisons of the hybrids, as expressed in potentialadded value of grain components, are summarized and compared, in Table 3below, to yellow dent corn. TABLE 3 Potential Added Value YieldComparison Yield Added value VARIETY Component (milling) $/# $/bushel($/bushel) Yellow Starch 67% 0.08 2.58 — dent Gluten 2.2#/BU 0.12 —Fiber 9#/BU * * — Embryo 5.3#/BU 0.20 0.49 — Steep water 0.20 — Aminoacid — 40.00/oz. — — (proline) 1851W Starch 70.2% 0.11 3.71 +1.13 Gluten3#/BU +0.73 Fiber 8#/BU * * +0.32 Embryo 5.3#/BU 0.20 0.54 +0.05 Steepwater 0.20 +0.40 Amino acid 3.2 oz./ 40.00/oz. — +127.00 (proline) BU

As shown above, 1851W grain (Colorado Sweet Gold variety) had a starchmilling yield of 70.2%, i.e., 33.7 pounds from each 56 pound bushel at15% moisture, while yellow dent corn yielded 67% starch (˜32.2 poundsper bushel). By way of example, food grade starch, at the time of thisapplication, is worth $0.08 per pound. 1851W starch does not requirebleaching for certain applications and was sold at $0.11 per pound (33.7#×$0.11=$3.71 per bushel for the hybrid). Yellow dent selling at $0.08per pound×32.2 pounds=$2.58 per bushel. The resultant added value in thehybrid is $1.13 per bushel. Additionally, the hybrid exhibits variousunique properties as described herein. Processing applications whereinchemical modification of the starch is not required result in higheradded value. For example, a $0.16 per pound savings for 33.7 pounds perbushel results in a $5.39 per bushel added value.

The gluten yielded by the hybrid was 3 pounds per bushel at 80% protein(dry-matter basis) as compared to 2.2 pounds per bushel at 60% proteinfor yellow dent corn. The hybrid gluten is essentially 100% digestible,whereas the yellow dent corn is only 48% digestible. Hence, 3 pounds perbushel @ 80%=2.4 pounds×100% digestibility=2.4 pounds available proteinper bushel of hybrid corn versus 0.64 pounds for yellow dent (2.2 poundsper bushel @ 60%=1.32 pounds per bushel×48% digestibility=0.64 poundsavailable protein per bushel). If, for instance, yellow dent derivedgluten is worth $0.12 per pound, then the 0.64 pounds of availableprotein per bushel is worth $0.4125 per pound. There is an additional1.76 pounds of protein available in the 1851W hybrid example, resultingin a $0.73 per bushel added value.

With regard to fiber, yellow dent corn yields 9 pounds per bushelcomprised of 23% starch and 10% protein, and is 38% soluble. The hybridexample disclosed in Table 3 yields only 8 pounds of fiber per bushel.However, the composition of that fiber is 8% starch and 20% protein, andthe fiber component is 72% soluble. Lower starch values and higherprotein and solubility values are considered positive results. Currentvalues of fiber are unknown. However, it is reasonable to assume thatadding 10% (protein) steep water to the fiber makes a 30% protein glutenfeed product that is competitive with the standard 20% market product.By way of example, this product is similar to distillers dried grains(“DDG”) in value. Estimating the worth at approximately $120.00 per tonversus $40.00 per ton (at 50% moisture) for the 20% gluten feed productadds value of $0.32 per bushel.

If the embryo fraction of the kernel is typically sold to oil extractorsat a price of $180.00 per ton, and yellow dent corn yields 5.3 poundsper bushel at 46.5% oil, then, 2.46 pounds at $0.20 per pound is worth$0.49 per bushel. The 1851W hybrid yields 5.3 pounds per bushel at 51.2%oil. The result is 2.71 pounds, that is worth $0.54 per bushel, or $0.05added value per bushel. Moreover, if the oil is extracted on-site andsubsequently sold to refiners, the extracted oil product may be worth upto $0.49 per pound. Present extraction technologies allow 90-95%efficiency. Hence, the hybrid develops $1.19 value (2.71pounds×90%×$0.49 per pound) as compared to yellow dent corn (2.46pounds×90%×$0.49), resulting in added value of $0.11 per bushel.Remaining is 2.8 pounds of meal that may be made into starter feeds orsold as regular gluten at $0.12 per pound for an additional added valueof $0.34 per bushel.

Next, if steep water value is estimated at $0.20 per pound for solubleproteins (provided the SO₂ used in the steeping process can beneutralized) at 2 pounds per bushel, there is an added value of $0.40per bushel.

Various amino acids that are used in both the food and pharma industriesmay be isolated from corn, provided they are presented in sufficientamounts. By way of example, if the worth of proline is estimated atapproximately $40.00 per ounce, and the instant hybrids containapproximately 3.2 ounces per bushel, the added value of an additional$127.00 per bushel results.

As shown in Table 4, without excessive and/or repeated steeping andrecycling during the wet milling process, the recovered gluten meal ofthe present invention, contains significantly more protein withincreased digestibility, less phosphorus, less ash, and significantlyless beta-carotene levels. The combination of these traits makes a novelfeed ingredient that demands a higher value. Currently in the marketplace, there is an estimated increased value of this type of productranging from $80.00-$150.00 per ton. Key market segments that couldutilize this type of product includes feed operations where the absenceof carotenoid pigments enhances the color of the flesh (trout) or thefat (swine, cattle), where the increased digestible protein lowers inputcosts, and for operations that are seeking alternative protein sourcesthat are not animal derived. TABLE 4 Gluten Meal Comparison TRAIT YELLOWGLUTEN 1851W GLUTEN Protein (%, db) 68.55-73.57 73.31-77.46 Crude Fat(%, db) 0.87-3.06 0.69-1.47 Ash (%) 2.93-4.45 1.67-2.90 Phosphorous (%)0.67-0.98 0.36-0.58 Beta-carotene (ug/100 g)  80.0-104.0 300.0-345.0Xanthophyll (mg/lb)  5.0-25.0 130.0-170.0

EXAMPLE 2

This example compares the substantially similar characteristics of thehybrid E8272 with those previously described herein for the hybrid1852W. The extraction techniques and comparative analysis are summarizedbelow.

A 1.159 kg sample of E8272 and a 1.158 kg sample of 1851W were wetmilled in a laboratory of the Center for Crops Utilization Research,Iowa State University (Ames, Iowa) to obtain high-quality corn starch,gluten meal, fiber and germ. The samples were steeped in 2.5 liters ofsolution containing 0.5% lactic acid and 0.2% SO₂ at 50° C. for 40hours. The steeped corn was strained and the volume and pH of steepwater measured. The steep water was then analyzed for dissolved solids.

The steeped corn was separated into several 200 gram fractions. Eachfraction was ground with 200 ml water in a 1-liter Waring blenderequipped with blunted blades and set at 50% speed for 4 minutes. Thecoarsely ground slurries were combined into a 4-liter bucket. One literof water was added to the slurry. The slurry was mixed with a spatulaand allowed to settle for 30 seconds, allowing the germ to float to thesurface. The germ was skimmed off the surface with a 7-mesh hand-heldskimming screen (pore size 2.8 mm) and placed into a 2-liter beaker.This procedure was repeated several times until essentially all freegerm was removed. The germ was mixed with another liter of water andstrained through a 16-mesh screen. The washed germ was then dried on thescreen for 24 hours in a large-capacity forced-air oven set at 50° C.The underflow (wash water) generated from the 16-mesh screen was mixedwith the degermed slurry.

The degermed slurry underwent fine grinding for 2 minutes in a 4-literWaring commercial heavy-duty blender equipped with sharp blades and setat 90% speed. The finely ground slurry was then strained through a7-mesh screen (pore size 2.8 mm) placed atop a 4-liter bucket. Thecoarse fiber fraction was scrapped off the screen using a spatula, mixedwith 1 liter of water, and resifted through the 7-mesh screen. Thecoarse fiber fraction was then mixed a final time with another literwater and sifted once again through the 7-mesh screen. The coarse fiberfraction was placed into a large stainless steel pan. The remainingslurry was then strained through a 50-mesh screen (pore size 0.3 mm)placed atop another 4-liter bucket. The fiber was scraped off the screenusing a spatula, mixed with 1 liter of water, and resifted through the50-mesh screen. The fiber fraction was then mixed a final time withanother liter of water and sifted once again through the 50-mesh screen.This fiber fraction was combined with the previously collected coarsefiber fraction and dried for 24 hours in a large-capacity forced-airoven set at 50° C.

The underflow (containing fine fiber and mill starch) was strainedthrough a 200-mesh screen (pore size of 0.075 mm) placed atop a 4-literbucket to separate the fine fiber fro the mill starch. The fine fiberwas scraped off the screen using a spatula, mixed with the decant water,and resifted through the 200-mesh screen. The fine fiber was then mixedwith another liter of water and sifted once again through the 200-meshscreen. The fine fiber was placed in a glass baking dish (separate fromthe coarse fiber) and dried for 24 hours in a large-capacity forced-airoven set at 50° C.

The remaining slurry (mill starch) was refrigerated at 4° C. and allowedto settle overnight for approximately 16 hours. After settling,approximately 4 liters of water were decanted from the mill starchslurry. The remaining slurry was mixed in a 10-liter glass bucket andadjusted to a specific gravity of 1.04. The adjusted slurry was thenpumped at a rate of 300 ml/in onto a starch table (20′ L×4″ W) set at a0.6 pitch. The gluten was collected in a 20-liter bucket placed at thedistal end of the starch table, as the heavier starch settled onto thetable. After the mill starch was exhausted, decant water was immediatelypumped onto the table at the rate of 300 ml/min to rinse the starchfraction. The starch was allowed to settle for 10 minutes and another 3liters of water were pumped onto the table at 300 ml/min to give thestarch a final rinse. Simultaneously, an additional 500 milliliters ofwater were placed in a squeeze bottle and used to wash any remainingsurface protein down the table. The starch was immediately scraped offthe table and dried for 24 hours in a large-capacity forced-air oven setat 50° C. before storing.

The gluten slurry was centrifuged at 6000 rpm for 20 min. The decantwater from the gluten slurry (rinse water) was tested for dissolvedsolids. The gluten solids were placed in a glass baking dish and driedin a large-capacity forced-air oven set at 50° C. for 24 hours.

Moisture content of solid fractions was determined in triplicate bydrying 2 grams of the fraction in a convection oven at 130° C. for 3hours according to AOAC standard methodology.

Dissolved solids in steep water was determined by drying the entirefraction in a large-capacity forced-air oven set at 50° C. for 24 hoursfollowed by drying in a convection oven at 130° C. for 3 hours accordingto AOAC standard methodology. Dissolved solids in rinse water wasdetermined by drying a 50 gram sample (in triplicate) in alarge-capacity forced-air oven set at 50° C. for 24 hours followed bydrying in a convection oven at 130° C. for 3 hours according to AOACstandard methodology.

An analytical comparison of the E8272 hybrid to the 1851W hybrid andstandard yellow dent corn is presented in Table 5. Similarly to 1851W,E8272 shows higher protein levels and lower levels of carotenoids thanstandard yellow dent corn. TABLE 5 Grain Comparisons of E8272 vs 1851Wand Standard Yellow Trait E8272 1851W Standard Yellow Crude Protein (%)*13.33 9.86 8.81 Crude Fat (%)* 5.01 4.49 4.21 Crude Fiber (%) 2.11 2.342.05 Ash (%)* 1.24 1.26 1.45 ADF (%)* 3.69 3.64 2.90 NDF (%)* 13.9213.24 11.35 Cellulose (%)* 3.44 2.73 2.65 Phosphorus (%)* 0.28 0.26 0.31Starch (%) 64.76 64.67 71.73 Beta Carotene (ug/100 g) 18.2 <0.05 107.5Xanthophyll (ug/100 g) <1.0 <0.08 4.08 Fatty Acids (% of total fat)Myristic(14:0) 0.12 0.03 0.00 Myristoleic (14:1) 0.08 0.00 0.00 Palmitic(16:1) 12.75 11.68 13.14 Palmitoleic (16:1) 0.23 0.13 0.12 Stearic(18:0) 2.83 1.93 1.94 Oleic (18:1) 25.53 22.43 23.77 Linoleic (18:2)51.7 59.42 56.42 Linolenic (18:3) 1.29 1.06 1.80 Arachidic (20:0) 0.150.46 0.45 Docosanoic (22:0) 0.28 0.27 0.27 Lignoceric (24:0) 0.00 0.200.19*Values are based on a 0% moisture basisTotal mass balance for all fractions was determined on dry basis.

Prior to wet milling, NIR analyses were performed on the grain, theresults of which are shown in Table 6. The E8272 hybrid has higherprotein and starch levels than the 1851W hybrid, and a lower oilcontent. TABLE 6 Grain Properties of E8272 Verses 1851W Trait E82721851W NIR Protein Content (%, db) 10.1 9.6 NIR Starch Content (%, db)71.1 67.0 NIR Oil Content (%, db) 3.85 4.25 Absolute Density (g/cc)1.302 1.285

The E8272 hybrid shows above average wet milling properties incomparison with other commercial hybrids. Mass balance calculated on drybasis shows that a 65.6% yield was obtained on the starch fraction,which falls on the high end of the range normally found among otherwhite dent corn hybrids (64%+/−2%) using this laboratory procedure. TheE8272 sample also yields a purer starch than is typically found amongother white corn hybrids. The protein content of the starch was 0.35%,dry basis, which is much lower than values typically found among whitecorn hybrids (0.6%+/−0.2%). It was previously demonstrated on acommercial basis that the 1851W had excellent separation of starch fromthe protein. According to this data, E8272 wet milling properties followa similar pattern to 1851W with the potential of generating even ahigher level of starch purity.

The gluten meal obtained from the 1851W lab sample reveals a proteincontent (53.0%, dry basis) that is higher than typically found amongother white dent corn varieties (45%+/−5%) using this lab procedure, seeTable 7 and 8. These procedures identify the enhanced characteristicsmaking the hybrids of this invention unique. TABLE 7 Lab Wet MillingMaterial Balance of E8272 Verses 1851W Fraction E8272 Yield (%, db)1851W Yield (%, db) Starch 65.6 65.2 Gluten Meal 9.3 8.8 Germ 8.1 9.7Coarse Fiber 7.9 7.9 Fine Fiber 3.7 3.0 Steep Water Solubles 4.3 3.8Rinse Water Solubles 1.0 1.2 Total Solids 99.9 99.6

TABLE 8 Product Quality of Solid Factions E8272 Protein 1851W ProteinE8272 Oil 1851W Oil Fraction (%, db) (%, db) (%, db) (%, db) Starch 0.350.42 0.059 0.046 Gluten Meal 45.6 53.0 2.42 1.74 Germ 13.3 14.2 39.440.7

EXAMPLE 3

This example illustrates the uniqueness of the pearl starch of 1851W andhow it is positioned in the grain. Susan Duvick, manager of the USDA-ARSQuality Trait Analysis Laboratory looked at the structure andfunctionality of the starch from the 1851W hybrid that had been milledat the Iowa State University Center for Crops Utilization Research. Thestarch was gelatinized and stored for a week, then analyzed withdifferential scanning calorimetry (DSC) to measure how much energy wasrequired to melt the crystallized starch. A typical corn starchgenerates a single, fairly uniform peak upon the same analysis. The DSCprofile for the 1851W starch showed the starch gelled in two phases asshown in FIG. 1.

To account for the two thermal events, the starch granules were studiedusing electron micrography. A kernel of 1851W was freeze fractured andthe starch granules were examined towards the tip and towards the crownof the kernel. Two distinct types of granules were found and they weredistinctly separated according to location. In the tip area, small,round granules were found as shown in FIG. 2. Towards the crown, large,angular granules were found as shown in FIG. 3. Although typical cornstarch exhibits a wide variety of granule shape and sizes, it does notexpress a distinct bimodality. Wheat starch, on the other hand, doesexhibit this sort of bimodal starch granule composition with its largeA- and small B-type granules. In wheat starch, the two types of starchgranules do differ in their physical and chemical properties. Thepresence of the small, round granules at the tip end along with distinctchannels provides an explanation for the rapid uptake of water inprocessing.

Analyses were conducted at USDA-ARS Quality Trait Analysis Laboratory,which examined the starch of E8272 from single kernel starch extraction,lab wet mill separation, and electron microscope examination of freezefractured kernels.

The bench top single kernel procedure involves steeping the kernels ofcorn to soften the kernel, manually removing the pericarp and germ,grinding the kernel and pouring the slurry through a nylon mesh tofilter out the fiber and large aggregates of endosperm and collect thestarch and water in a beaker. The starch is allowed to settle and iswashed several times to remove the residual protein and fiber. Starchsettling rates were determined by measuring absorbency verses time. Itwas observed that the starch of 1851W settled faster than most otherhybrids that indicated large, dense starch granules which was confirmedby the electron micrographs. When E8272 starch was compared to 1851W, itsettled out even faster than 1851W as shown in Table 9. TABLE 9 StarchSettling of Starch Measured by Absorbance Time (min.) 1851W E8272 1.01.590 1.528 2.0 1.581 1.528 4.0 1.555 1.427 6.0 1.386 1.126 8.0 1.1410.847 10.0 0.931 0.650 12.0 0.773 0.506

Unexpectedly, examination of the starch granules of E8272 under anelectron microscope revealed that the fast rate of settling for E8272was not due to density but due to holes in the starch granules due tointrinsic enzyme activity. Starch granules with this type ofconfiguration were not apparent in any of the other hybrids andcertainly were not been observed in any conventional corn hybrids. Thistype of starch configuration could potentially be the next step insignificantly reducing steep times in alkaline cooking or any other wetmill processing.

Grain of E8272 was analyzed in the laboratory for comparison to the1851W model for making tortillas. The following treatments were used:

-   -   90° C. cooking temperature, 25 minute cooking time, with a 7        hour steep time    -   90° C. cooking temperature, 25 minute cooking time, with a 5        hour steep time    -   90° C. cooking temperature, 25 minute cooking time, with a 4        hour steep time    -   85° C. cooking temperature, 25 minute cooking time, with a 4        hour steep time

In treatment 1, the resulting masa was extremely wet and not useable formaking tortillas. This indicated that the starch responded like thestarch settling experiment where it absorbed water faster than 1851W. Intreatment 2 and 3, the steep time was reduced, however, the masa wasstill too soft and sticky for sheeting. By reducing the temperature to85° C. in treatment 4, high-quality tortillas could be made.

The alkaline cooking model indicates that E8272 can be cooked at muchlower temperatures than normal (85° C. vs 95° C.), lower cook time (25minutes vs 35 minutes), and use significantly less steep time (4 hoursvs 12 hours).

EXAMPLE 4

This example illustrates the impact of the uniqueness of the 1851Wstarch and protein complex on alkaline cooking, and especially, tortillaproduction. Dr. David Jackson, at the University of Nebraska-Lincoln'sFood Processing Center, developed a standardized, pilot-scalenixtamalization and tortilla production procedure in which properquantification of input and output could be performed.

After a preliminary cooking test to determine the extremes in processingconditions, Dr. Jackson developed a central composite response surfacedesign to determine the processing combinations that would be used forthe study. In complex processes, such as tortilla cooking andprocessing, response surface experimental designs allow fewer trials tobe run to understand a wide range of process conditions. When completed,the model serves as a graphic reference to determine optimum results. Itmay reveal, for example, the cooking and steeping processes that providethe lowest dry matter loss and result in good quality tortillas andtortilla chips. In addition, it could serve as a valuable tool for plantbreeders to evaluate and screen new products without having to producecommercial quantities.

Following the resulting design, Jackson's group cooked corn whilecollecting data on a wide range of process parameters, including cornsolids loss and distribution within cook, steep, and wash waters; yieldsof intermediate products and finished tortillas; and subjectiveobservations of processing ease and tortilla quality.

A response surface model reflecting cooking and tortilla-makingproperties revealed that masa sheetability was higher for 1851W whencooked at temperatures less than 93° C. for cooking times similar tothose for conventional food-grade hybrids, but for shorter steepingtimes (i.e., 10.5 hr of steeping compared with 12.0 hr for conventionalfood-grade corn). It was also discovered that for 1851W a product withhigher dry matter (tortilla yield) could be achieved with steep times asshort as 6 hr. Overall, the white corn hybrid displayed relativeinsensitivity to steep time compared with conventional hybrids.

Shortened steep times offer manufacturers of masa-based products severaladvantages. First, nixamalization, because it is a batch process, can bea manufacturing bottleneck. With shorter steep times, fewer tanks wouldbe required at any given time, which would increase efficiency. In someoperations, downstream forming, baking, and frying equipment may not beoperating at full capacity. Under these conditions, a reduction in steeptime might offer the potential to increase production capacity.

Steep tolerance could additionally offer another significant advantagein reducing waste when equipment fails. In addition, with a wide steeprange, a processor might be able to enhance the robustness of theprocess by reducing cook times and extending the steep times.

A chromatographic profile of the amylose and amylopectin was conductedon the 1851W starch by Dr. David Jackson at the University of Nebraskaas shown in FIG. 4. The peak that comes out first is amylopectinfollowed by amylose. This is an unusual profile in that normally mostcorn starch can be easily separated by this technique. In the case of1851W, there appears to be a range of starch polymers that fall withinthe full spectrum of amylose and amylopectin, and even into what wouldsometimes be called intermediate material.

Dr. David Jackson completed calculation estimates for amylose andamylopectin content of 1851W starch. The determined values at that timewere 50.2% amylose and 49.8% amylopectin. However, the fact that inalkaline cooking 1851W required less steep time, reduced cook time, andreduced temperature, it was expected that there should be a higheramylopectin content. It was theorized that the branch chain lengths ofthe amylopectin starch in 1851W could be increased in length, and couldpossibly give a false reading for amylose.

Recently, Dr. Jay-Lin Jane at Iowa State University used gel permeationchromatography and iodine potentiometric titration to estimate theamylose and amylopectin content. Those results indicated the following:Hybrid Amylose % Amylopectin % Standard Yellow 35.1 64.9 1851W 31.9 68.1E8272 30.0 70.0By comparing the Blue Value of the iodine test to the total carbohydratelevel, it was also estimated that the length of the amylopectin chainsof 1851W starch are longer than normal.

In relative viscosity analysis (RVA), the starch had an initial peakviscosity 22% higher than commercial corn starch. Subsequent testsmeasured viscosity held at a constant temperature with stirring over aperiod of time. When compared with the results from commercial starch,the starch exhibited 31% higher viscosity after the holding period. Withhigher initial viscosity and better viscosity retention, the hybrid'sstarch may offer some of the properties of a modified starch withoutmodification.

At the University of Illinois, Steve Echkoff and Yolanda Lopes created asmall-scale laboratory procedure to quickly evaluate corn samplesintended for use in masa and tortillas. Nine samples were evaluatedusing the procedure. The researchers cooked 100-gram samples of corn inErylenmeyer flasks for a variety of cook times. After cooking, the cornwas allowed to steep in the flasks at room temperature for 18 hr. Aftersteeping, the researchers ground the masa, shaped it into a ball, andflattened it with a manual tortilla press. The resulting tortilla wasbaked and cooled. Both the masa and the finished tortilla were subjectedto additional tests, including texture profile analysis (TPA). Used toevaluate tortilla-making potential, TPA measures qualities such ashardness, adhesiveness, cohesiveness, chewiness, gumminess, andspringiness.

On the masa itself, the 1851W was among the few samples that absorbedclose to the targeted minimum moisture content of 51% at the shortestcook time of 30 minutes. In addition, the hybrid exhibited a flatterresponse to changes in the cook time compared with the other sample.

Adhesiveness is measured as the total work required to release acylinder of masa from the texture analyzer probe. Table 10 shows thatmasa adhesiveness increased with cook time for yellow corn hybrids while1851W showed a decrease by almost 50% in going from a 30-minute cooktime to a 90-minute cook time. Another Wilson Genetics white hybrid,1780W, also decreased with cook time but to a lesser extent. Practicalsignificance of adhesiveness is that too high of adhesion results in themasa sticking to the equipment and causing problems in the rolling andcutting operations. Too little adhesion results in brittle tortillas.TABLE 10 Affect of cook time on masa adhesiveness for two yellow and twowhite corn hybrids. Masa Adhesiveness (g) Standard Hard Cook Time SoftEndosperm (min.) 1851W 1780W Yellow Yellow 30 110 72 44 8 60 82 50 58 2190 62 60 78 45 120 70 38 90 63

Next, the texture analyzer measured the force and distance required topuncture the finished tortillas—an indication of tenderness. This forcevaried widely between the corn samples at the 30-minute cook time withthe 1851W having the lowest puncture force required. In general, allhybrids tested decreased in puncture force with cook time. Most of thehybrids, however, required 90- to 120-minute cooking times to approach1851W's tenderness at only 30 minutes of cooking time.

Cohesiveness is a measure of the strength of masa dough. The strength isdetermined as to how well the masa sample withstands a secondcompression (deformation) relative to the first compression. Lowcohesiveness means that when the texture analyzer compresses the doughonce, there is an internal disruption of the structure to the point thatit takes little force to compress the dough further. The cohesiveness isthought to relate to the sheeting characteristics of masa dough and tothe final thickness of the tortilla. Table 11 shows that 1851W hybridwas markedly different than the other hybrids. For the 1851W hybrid,cohesiveness decreased dramatically with cook time, while cohesivenessincreased for the standard soft yellow corn. Basically, the resultsconfirmed the trends that were found with the pilot-scale study in that1851W responds differently than normal hybrids and it can reduce cooktime, steep time, and cook temperature. TABLE 11 Affect of cook time oncohesiveness for two yellow and two white corn hybrids. MasaCohesiveness Ratio Hard Cook Time Standard Endosperm (min.) 1851W 1780WSoft Yellow Yellow 30 0.178 0.153 0.143 0.148 60 0.162 0.151 0.153 0.14490 0.153 0.155 0.163 0.147 120 0.154 0.160 0.177 0.154

Although the uses of the present invention have been disclosed primarilywith respect to foods and feed additives, this is not deemed to limitthe scope of this invention. The present invention may be used in otherfields of industry, e.g., paints, plastics, paper, wallboards. Thepresent invention is embodied in hybrid corn having enhancedcompositional characteristics and improved derivative products.Regardless of the specific application of the instant invention, themethodology details are calculated according to protocols well known inthe art, as well as those disclosed herein. Further, the refinement ofsaid necessary calculations is routinely made by those of ordinary skillin the art and is within the ambit of tasks routinely performed by themwithout undue experimentation.

While the above description contains much specificity, thesespecificities should not be construed as limitations on the scope of theinvention, but rather exemplification of the preferred embodimentthereof. That is to say, the foregoing description of the invention isexemplary for purposes of illustration and explanation. Withoutdeparting from the spirit and scope of this invention, one skilled inthe art can make various changes and modification to the invention toadapt it to various usages and conditions. As such, these changes andmodification are properly, equitably and intended to be within the fullrange of equivalence of the following claims. Thus, the scope of theinvention should be determined by the appended claims and their legalequivalents, rather than by the examples provided herein.

When made with masa from white corn, tortillas, tortilla chips and cornchips project a more upscale image to consumers. In the past, this imagewas well deserved because white corn commanded a higher price due to itslower yields. Today, seed companies have addressed white corn's yieldissues and are focusing on adding value for food manufacturers. TheZimmerman Brand 1851W White Corn Hybrid from Wilson Genetics, L.L.C.,Harlan, Iowa, for example, may actually help manufacturers of masa-basedproducts reduce cost, improve production efficiency and increasemanufacturing flexibility.

Deposit Information

Deposit of the Wilson Genetics, LLC's corn inbreds WEBF428C and WICY418Cdisclosed above and recited in the appended claims has been made withthe American Type Culture Collection (ATCC), 10801 University Boulevard,Manassas, Va. 20110. The date of deposit was Jan. 22, 2001. The depositof 2,500 seeds were taken from the same deposit maintained by WilsonGenetics, LLC since prior to the filing date of this application. Allrestrictions upon the deposit have been removed, and the deposit isintended to meet all of the requirements of 37 C.F.R. '1.801-1.809. TheATCC accession numbers are PTA-2924 and PTA-2925 respectively. Thedeposit will be maintained in the depository for a period of 30 years,or 5 years after the last request, or for the effective life of thepatent, whichever is longer, and will be replaced as necessary duringthat period.

1-61. (canceled)
 62. A method of extracting starch of a white cornhybrid, comprising the steps of: a) selecting grain of a white cornhybrid producing by wet milling a starch fraction that undergoes twophased gelling upon heating of the crystallized form of said starch. b)wet milling said grain selected according to step a) on an identitypreserved basis; and c) extracting the starch fraction as a product ofsaid wet milling.
 63. A method of extracting starch of a white cornhybrid according to claim 1, further comprising incorporating saidstarch fraction into food products.
 64. A method of extracting starch ofa white corn hybrid according to claim 1, further comprisingincorporating said starch fraction into laundry starch.
 65. A method ofextracting starch of a white corn hybrid according to claim 1, furthercomprising incorporating said starch fraction into paper coating.
 66. Amethod of extracting starch of a white corn hybrid according to claim 1,further comprising incorporating said starch fraction into textile. 67.A method of extracting starch of a white corn hybrid according to claim1, further comprising incorporating said starch fraction into foodproducts.
 68. A method of extracting starch of a white corn hybrid,comprising the steps of: d) selecting grain of a white corn hybridhaving greater than 65.0% starch on a dry weigh basis; e) wet millingsaid grain selected according to step a); and f) extracting the starchfraction as a product of said wet milling.
 69. A method of selecting awhite corn hybrid for wet milling, comprising the step of selectingkernels of said white corn hybrid based on starch granules located inthe tip area of said kernel are smaller and rounder compared to thestarch granules located in the crown area.
 70. A method of selecting awhite corn hybrid for wet milling, comprising the step of selectingkernels of said white corn hybrid based on 50% of said kernel starchgranules located in the tip area of said kernel have a diameterapproximately less than 2 microns.
 71. A method of selecting a whitecorn hybrid for wet milling, comprising the step of selecting kernels ofsaid white corn hybrid based on 50% of said kernel starch granuleslocated in the crown area of said kernel having a diameter approximatelygreater than 6 microns.
 72. A white corn kernel having starch granuals,wherein approximately more than 50% of said starch granules have adiameter less than 2 microns in the lower 25% of the kernel.
 73. A whitecorn kernel having starch granules in the upper 25% of the kernel,wherein more than 50% of said starch granules have a diameter greaterthan 6 microns.